Anybody here with experience in Extreme Cold (-20F)

[TomK]

I'm still pretty new to this EV thing. Just got my 2015 Spark 3 weeks ago here in Minnesota (MPLS/ST Paul area) with 57k miles on it. Battery appears to have 15kWh left on it. The car was brought to MN in 2020 from CA.

I live in rural MN and commute every day to the city, about 26 miles each way. I charge on a L2 over night to between 80-90% (haven't figured out how far ahead to set the departure time yet). I can charge at work using 110V/12A and easily charge back up to 80-90% during the 9 hour period.

Right now with temps in the morning around 55-60 and evening around 80, I have been using around 40% of the battery to/from work.

I realize these cars were not made with cold climates in mind and i will probably be pushing the limits of the range during the winter. Everything i've been reading about cold weather is starting to worry me a bit.

My goal is to pre-heat/condition the car inside my barn before leaving in the morning but then it will be outside all day at work. Not sure how well pre-conditioning will work when only on a L1/12A charger. I think the car will make it depending on how much heat i need/want to use. My biggest concern is that i will be able to stay in the 20-80% battery SoC. Right now i'm on the charger 2 times per day but only putting about 35-40 back in each time.

I'm planning for maybe 1/2 range worst case, so needed around 80% each way. Will the additional discharging/charging cycles in the winter cause issues with the battery?

Anyone here with some real world experience on range and needing to use the defrost during cold weather driving? A lot of information about cold weather suggests temps in the 20-30F - which to be fair, could be cold for some but around here in January we call that a heat wave.

 

[Randy960]

I live outside Buffalo, NY (so not quite as cold, but still dips into the negatives) and for the past several years had a similar commute (I think 24 miles). I charged my car in my garage overnight, and even on the coldest days I could make it there and back on a charge as long as I wasn't driving over 70 or so on the highway. Or with charging on level 1 or 2 at work, I was basically fully charged before I went home, and could drive as hard as I wanted to. I would generally precondition when it was cold, and it seemed to do so on level 1 with minimal draw from the battery. Starting out with my car cold outside, it obviously took more power to warm up, but the times I had to do that I was charging at work anyway.

 

[TomK]

Thanks, that's encouraging. There is a couple free L2 charging stations at a Goodwill just a few miles from my work, so i can always stop there and pre-heat the car a little further. Some of my co-workers/friends are already laughing at my "range anxiety" but i wouldn't even call it that, just trying to make a plan to get me where i need to go. So far, i have not had to change my routine one bit, including extra trips during lunch. Winter might be different with less range and time to recharge but nothing that cannot be worked around.

 

[Infinion]

The biggest challenge is for Spark EV owners who can't stay plugged in overnight, and temperatures start dipping below 32ºF.
This is because below freezing, lithium chemistries can't be recharged, and with regen, this would cause cell damage.
So the car limits (but still allows) the regenerative braking that charges the battery. It also runs a 2.5kW PTC battery coolant heater to try and get temperatures above around 40ºF. The PTC heater in the cabin is also a hog, and can take as much as 8kW with the addition of the AC compressor to defog.

If you stay plugged in in any of the charging modes, the car will maintain 40ºF - 55ºF with a remote start preheat. I don't have specifics on what temperatures it keeps with departure and remote start, but I think it would be more aggressive/ambitious.
During L1/L2 charging, all of the power will go to the battery coolant heater until the battery is 3-5 degrees above freezing. L1 will only draw up to 1kW at 12A and even less at 8A, meaning it takes longer to begin charging.

Here are some screenshots I took in 2022 of a L1 charging session.



Pay attention to:
the top left "battery coolant" and "Batt temp Avg"
center top "Batt Heat"

In order the screenshots were taken at
6:42PM
6:46PM
6:59PM
7:28PM
and 7:36PM

So it took just under an hour to start charging from a cold-soaked battery just 6 degrees below freezing.

The second last screenshot shows charging is moving forward without battery heat at 2ºC above freezing.
The last screenshot shows that I remote started the vehicle, and the full heater power was drawn, along with full cabin heat, almost 8kW despite the level 1 charger only bringing in 1kW.

The data can be plotted and a trendline to find the rate of heating per minute that you could expect on a level 1 charger.
It would be a good winter community project to include more sessions on L1 and L2 chargers, and with even deeper cold-soaked batteries.

 

[SmokeyPete]

Unless I'm missing something, the only way to practice best practices of staying below 80% SOC during freezing temperatures is to play around with the annoyingly difficult "departure time" settings so that the car is always slow blinking the green blinking charge indicator?

 

[TomK]

Unless I'm missing something, the only way to practice best practices of staying below 80% SOC during freezing temperatures is to play around with the annoyingly difficult "departure time" settings so that the car is always slow blinking the green blinking charge indicator?

I have been experimenting with this and it seems to be very difficult to hit 80%. I'm typically between 75-85%, but most of the time i end up on the high end still. On L2, i set departure time to 1 1/2 hrs past and seems to work out OK. This morning i got out there with 50 minutes left and i was at 86% SoC. So far on L1 running at 12A, i think 3-4 hours past the desired departure time will get me close to 80%. I'm guessing temperatures will also throw a wrench in all this logic come winter and i'll have to change the times accordingly.

It's probably the most annoying lack of feature that i didn't know i needed before buying this vehicle. It seems so simple to be able to just tell it to go to 80% and just keep it there. They even have the feature for charge to 40% immediately but i don't think they allow adjustment of this value do something a bit higher.

 

[SmokeyPete]

It's part of the reason I purchased (and built) an OpenEVSE. In addition, perhaps setting charging at 6A or 8A 240v will give you more flexibility in your charging regime. There is new research that charging at lower amperage may slightly benefit your battery life.